Gun-type adhesive applicator



April 11, 1961 J. s. KAMBORIAN GUN-TYPE ADHESIVE APPLICATOR 2 Sheets-Sheet 1 Filed Jan. 7, 1959 INVENTOR. (70606 ilamwm BY www April 1961 J. s. KAMBORIAN 2,979,234

GUN-TYPE ADHESIVE APPLICATOR Filed Jan. 7, 1959 2 Sheets-Sheet 2 INVENTOR.

fMQZW/ W United States Patent I GUN-TYPE ADHESIVE APPLICATOR Jacob S. Kamborian, West Newton, Mass. International Shoe Machine Corp., 292 Main St., Cambridge, Mass.)

Filed Jan. 7, 1959, Ser. No. 785,494

* Claims. (Cl. 222146) This invention relates to apparatus for applying adhesive and more especially to a gun-type applicator which may be held in the hand and moved about freely to apply hot adhesive to parts to be joined.

The principal objects of the invention are to provide a light-weight gun-type applicator which can be comfortably held and controlled for application of adhesive constantly or intermittently to parts which are to be united; to provide a gun applicator for receiving adhesive in solid form so that the operator does not have to handle liquid adhesive when replenishing the gun; to provide a guntype applicator which cannot be accidentally choked by the operator inserting too much adhesive at one time; to provide a gun in which melting of the adhesive is controlled to correspond substantially to the rate of use of the adhesive; to provide an apparatus in which air pressure is employed to expel the adhesive thereby to efiect uniform flow and uniform quantity; and to provide apparatus which can be easily cleaned and maintained in working order.

As herein illustrated, the apparatus comprises a barrel and hand grip attached thereto, to hold the barrel upright, a chamber at the lower end of the barrel, a bore extending from the upper end of the barrel downwardly toward the chamber but terminating short thereof for receiving solid adhesive, means for melting the adhesive of the bottom of the bore, a port connecting the lower end at the bore to the chamber through which the liquid adhesive may flow, a valve supported adjacent the lower end of the port, a nozzle extending from the chamber at the lower end of the barrel, substantially diametrically opposite the handle, and means for supplying air under pressure to the liquid adhesive in the chamber for simultaneously closing the valve and ejecting liquid adhesive from the nozzle.

The invention will now be described in greater detail with reference to the accompanying drawings wherein:

Fig. 1 is a vertical section through the applicator gun;

Fig. 2 is an elevation. as seen from the right-hand side of Fig. 1;

Fig. 3 is a plan view of Fig. 1;

Fig. 4 is a bottom view of the applicator;

Fig. 5 is a cross-section of a stick of solid adhesive shaped to fit into the bore of the gun; and

Fig. 6 is a combination wiring and pressure diagram.

Referring to the drawings, the applicator comprises a barrel 10, to which there is fastened a handle 12 for supporting the barrel in an upright position, as shown in Fig. 1. The barrel has at its lower end a chamber 14 and a pair of spaced parallel bores 16 and 18 of different cross-sectional diameter extending downwardly from the upper end of the barrel toward the chamber 14, the bore 16 of larger diameter terminating short of the chamber and the bore 18 of smaller diameter extending into the chamber. The bore 16 is adapted to receive solid adhesive in the form of a stick of substantially corresponding cross-section, as shown in dot and dash lines at 20 (Fig.

2 1) and in full lines (Fig. 5) and has at its lower end a well 22 of smaller diameter into which adhesive melted from the lower end of the stick gravitates. The lower end of the stick is supported above the well by a shoulder 24, formed at the junction of the lower end of the bore 16 and the mouth of the well 22. A port 26 extends from the bottom of the well into the chamber 14 through which adhesive, which collects in the well, can flow into the chamber. Radially disposed grooves 28 are provided at the bottom of the well which intersect the port 26 so as to prevent stagnation of adhesive at the periphery of the Well and hence to maintain good flow therefrom into the chamber. A ball valve 30 is supported at the lower end of the port 26 by a cage 32 which has at its lower end a screw threaded head 34, by means of which it is removably screwed into a threaded opening 36 at the bottom of the chamber. Normally, the ball rests on a pin 38 fixed transversely of the cage 32, as shown in dotted lines, thus the port 26 is opened and adhesive is free to how from the well into the chamber. Ports 40 are provided at the bottom of the cage, for a purpose which will appear hereinafter.

A nozzle 42 extends downwardly at an angle from the chamber 14, at the bottom of the barrel, substantially diametrically opposite the handle 12 and has screwed into it a tip 44 containing a check valve 46 which is spring pressed in a direction normally to resist discharge of adhesive from the chamber 14.

A heating element 48 is disposed in a chamber 50 adjacentv the chamber 14 and extends upwardly along the barrel to a point adjacent the well so that heat supplied to the lower end of the barrel will melt the adhesive from the lower end of the stick 20 and keep the adhesive melted within the well 22 and the chamber- 14. A thermostat 49 is employed in conjunction with the heating element to prevent excessive heating and to control melting so that melting does not proceed beyond the need for adhesive. In other words, the barrel is not heated so much as to melt the stick beyond the place of its contact with the shoulder 24. As shown in Fig. 6 the heating element and thermostat 48 and 49 are connected by way of conductors 51, 53 and a switch 55 to line current at L.

As the adhesive is melted from the stick it fills the well and flows through the open valve into the chamber 14, filling the latter, and entering the cage 32 through the ports 40.

An elbow 52 (Fig. l) is screwed into the upper end of the bore 18 for connection to an air supply line 54 for supplying air under pressure to the adhesive within the chamber 14. When pressure is admitted to the chamber 14 the valve 30 is closed so that there is no chance for the pressure to enter the well 22 and expel the liquid adhesive and stick from the bore 16 and at the same time opens the check valve 46 so as to eject liquid adhesive from the tip 44. A suitable solenoid valve 56 for controlling the flow of air from the source 54 to the bore 18 is provided and is controlled by a trigger 58 mounted on the handle 12 so as to be conveniently operated by the thumb. As shown in Fig. 6 the switch 58 closes a circuit through the solenoid 56a of the solenoid operated valve 56 so as to open the valve. A regulator R may be placed in the line 54 to control the pressure and a into the bore. The specific advantage of this is to make it necessary to use stick adhesive specially prepared for this applicator, the character of which is known to be suitable for dispensation from this applicator according to the proportions in which it is made and to discourage the use of inferior adhesive which can readily render the applicator unfit for use.

To still further insure proper operation of the apparatus, and as pointed out heretofore the well 22 is provided at the lower end of the bore 16 for the purpose not only to collect adhesive as it melts from the lower end of the stick but also to prevent the stick from being forced downwardly against the top of the port 26, which would force the adhesive in the chamber 14 if the latter were already filled upwardly into the bore 18 where it would accumulate in the course of time to choke the package because of its rather small diameter and thus render the device inoperative.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.

I claim:

1. An applicator gun comprising a slender light weight barrel of substantially circular cross-section and hand grip attached to the lower end, to hold the barrel upright, a chamber at the lower end of the barrel, a bore extending from the upper end of the barrel downwardly toward the chamber but terminating short thereof for receiving a stick of solid adhesive of substantially corresponding cross-section, a well of smaller cross-section than the bore at the bottom, a ledge at the junction of the lower end of the bore and tip of the well for supporting the lower end of the stick with adhesive at the top of the well to allow adhesive melted from the lower end of the stick to flow into the well without obstruction, a port connecting the bottom of the well to the chamber through which melted adhesive in the well can flow to the chamber, a normally open valve supported at the lower end of the port, a nozzle containing a check valve normally closing against discharge of adhesive from the chamber, said nozzle inclining forwardly and downwardly from the chamber opposite the handle, a rib projecting into the bore containing a passage of smaller diam- 4 eter than the bore parallel thereto, the upper end of which is adapted to receive a nipple fitting for connection to a source of air pressure and the lower end of which terminates at the top of the chamber, laterally of the valve, said passage being adapted to conduct air under pressure to the chamber simultaneously to close the valve at the lower end of the port and to force the adhesive through the check valve in the nozzle, and a trigger on the handle operable to control admission of air to said last-named means.

2. An applicator gun comprising a barrel and a hand grip attached thereto, to hold the barrel upright, a chamher at the lower end of the barrel, spaced bores extending from the upper end of the barrel downwardly, one terminating short of the chamber and the other extending into the chamber, the shorter bore being adapted to receive a stick of solid adhesive of substantially the same cross-section, means adjacent the lower end of the shorter bore for melting the adhesive, a port connecting the bottom of the shorter bore to the chamber, a valve cage screwed into the bottom of the chamber and supporting a ball valve adjacent the underside of the port, a nozzle containing a check valve therein extending angularly downward from the chamber at the lower end of the barrel and a trigger on the handle for controlling delivery of air under pressure to the upper end of the longer bore.

3. An applicator gun according to claim 1, wherein there is a heating element disposed in the barrel at the lower part, adjacent the lower end of the bore and the chamber.

4. An applicator gun according to claim 1, wherein the upper end of the barrel has a hook projecting therefrom for supporting the gun in suspension when not being used.

5. An applicator gun according to claim 1, wherein the bottom of the barrel has a plurality of radially disposed quarter circular grooves extending downwardly into the centrally disposed port.

References Cited in the file of this patent UNITED STATES PATENTS 

